1. Field of the Invention
The present invention relates to a system and method of managing a network state in a mobile radio communication system. In particular, the present invention relates to a network state management system and a network state management method utilizing the system which can compatibly manage the state of a network in which base station controllers and base station transceiver subsystems are linked through a plurality of trunks in a code division multiple access (CDMA) communication system and a personal communication service (PCS) system.
2. Description of the Related Art
Generally, if a certain mobile unit subscriber selects a terminating telephone number and transmits a call signal thereto in a mobile radio communication system, the corresponding base station receives a radio frequency signal transmitted from the originating mobile unit, and calls the terminating mobile unit through a calling channel. At this time, if the terminating mobile unit responds, a speech channel is provided between the two mobile units to achieve call communications. Here, respective base stations repeat the radio communications attempted by a plurality of mobile units located in a predetermined service area. A plurality of base station controllers are provided in a mobile radio communication system, and each base station controller controls a plurality of base stations.
However, in case of performing the call communications utilizing the currently defined communication protocol, a mobile unit may fail to receive a communication control signal transmitted from a base station in a special condition, or the base station may fail to receive the communication control signal transmitted from the mobile unit to the base station in a special condition, resulting in that the call communications between the terminating and originating mobile units may not be performed.
In order to manage such system troubles, a mobile radio communication system is provide with a network state management device. A typical network state management device detects the state of the network in which respective base station controllers or base stations under the control of a base station manager are linked other base stations or base station controllers through a plurality of trunks, outputs the resultant signal to a display device, and outputs an audio alarm to a loudspeaker.
FIG. 1 illustrates a network state management device for managing the trunk link state of the network between a typical base station controller and base station used in a mobile radio communication system.
Referring to FIG. 1, a certain base station controller 104 in a mobile radio communication system is connected to a base station 100 through two trunk transmission devices 101 and 102, and a plurality of trunk lines are connected between the two trunk transmission devices 101 and 102. Here, the base station controller 104 is provided with a state management processing section 104a, and detects whether the link state of the trunks T1 and T2 of the corresponding network is in a normal state or in an abnormal state utilizing information sensed by the trunk transmission device 102 by hardware. Specifically, as shown in FIG. 1, the trunk transmission device 102 provides the trunk state information 105a, which is obtained by sensing the link state of the trunks T1 and T2 by hardware, to the state management processing section 104a in the base station controller 104 through a separate control line.
Meanwhile, the base station 100 is also provided with a state management processing section 100a, and detects whether the link state of the trunks T1 and T2 of the corresponding network is in a normal state or in an abnormal state utilizing information sensed by the trunk transmission device 101 by hardware. Specifically, as shown in FIG. 1, the trunk transmission device 101 provides the trunk state information 105b, which is obtained by sensing the link state of the trunks T1 and T2 by hardware, to the state management processing section 100a in the base station 100 through a separate control line.
Accordingly, whether a normal routing of the call from the region between the base station controller 104 and the base station 100 to the remote network is possible or not is determined in accordance with the link state information of the corresponding links T1 and T2 sensed by hardware by the state management processing section 100a of the base station 100 and the state management processing section 104a of the base station controller 104 as shown in FIG. 1.
Also, even in case that a normal routing of the call is performed from the region between the base station controller 104 and the base station 100 to the remote network, the load share with respect to the links T1 and T2 should be done. At this time, the normally operable links are identified in accordance with the link state information of the corresponding links T1 and T2 sensed by hardware by the state management processing section 100a of the base station 100 and the state management processing section 104a of the base station controller 104, and then the normal load share is performed based on the identified result.
However, the conventional network state management device as described above only depends on the state information of the same trunk links T1 and T2 connected to the base station controller 104 and the base station 100 which is separately sensed through the respective trunk transmission devices 101 and 102 connected to the base station controller 104 and the base station 100. Accordingly, the base station controller 104 or the base station 100 determines whether to perform the routing only using the state information of the trunk links T1 and T2 provided thereto by hardware. As a result, if the state information of the trunk links T1 and T2 currently provided to the base station controller 104 is not consistent with that provided to the base station 100, serious problems may occur in routing or load share.
For example, we assume that two trunk links T1 and T2 exist between the base station controller 104 and the base station 100 via the trunk transmission devices 101 and 102 as shown in FIG. 1, the base station controller 104 identifies T1 and T2 as normal trunks based on the information provided by hardware, and the base station 100 identifies T2 only as a normal trunk based on the information provided by hardware. In this case, the base station controller 104 and the base station 100 cannot mutually perform normal data transmission and reception utilizing the trunks T1 and T2. In other words, the base station controller 104 identifies both T1 and T2 as the normal trunks and thus attempts to perform the load share with respect to the trunks T1 and T2, but the base station 100 attempts to perform the load share with respect to the trunk T1 only, resulting in that the normal data transmission and reception cannot be achieved through the two trunks.
As a result, in case of managing the link state of the trunks T1 and T2 using the conventional network state management device in a mobile radio communication system, connection of the call for calling the terminating mobile unit may fail, or the call communications between the originating and terminating mobile units in use may be cut off, thereby deteriorating the speech quality of the whole mobile radio communication system.
Accordingly, the present invention is directed to a system and method of managing the network state in a mobile radio communication system that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a system and method of managing the network state in a mobile radio communication system whereby two processors can mutually exchange the state information of bidirectional trunk links by an on-line processing for the compatible management of the network state.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the network state management system in a mobile radio communication system comprises a first processor, a first trunk transmission device connected to the first processor, a second processor, a second trunk transmission device connected to the second processor, and a plurality of trunks connected between the first and second trunk transmission devices, wherein the first and second trunk transmission devices sense and reconstruct link state information of the trunks so that the first and second processors can recognize the reconstructed link state information, and the first and second processors mutually exchange the reconstructed link state information.
In another aspect of the present invention, there is provided a method of managing the network state in a mobile radio communication system, comprising the steps of providing a test packet at predetermined intervals and transmitting the test packet mutually between at least two processors, and identifying a link state of trunks for connecting the processors utilizing the test packet.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.